A liquid crystal display panel is mainly composed of a color filter substrate and an array substrate which are cell-assembled and a liquid crystal layer therebetween. Here, red, green, and blue color filters in an array arrangement are provided on the color filter substrate to achieve color display.
In the process that the back light emitted from a back light module is transmitted through red, green, and blue dye molecules in red, green, and blue color filters so as to display red light, green light, and blue light, since brightness loss will occur after the light passes through red, green, and blue dye molecules in color filters (typically, 70% of the brightness of the back light will be lost) such that the utilization of the back light is relatively low, a manner of further increasing the energy consumption of the back light is required to weaken the impact of color filters on the brightness loss of the back light.
It is one of the manners for solving brightness loss of back light in the prior art to replace the dye molecules in red, green, and blue color filters with photoluminescent particles binding normal organic ligands, such as quantum dots (simply referred to as QDs), i.e., forming a quantum dot color filter film. The loss of the back light brightness due to the color filter is reduced by the light emission principle that electrons on the valence band of luminescent particles, such as quantum dots, etc., under the light irradiation of back light are excited by the energy of photons to transit to the conduction band and energy is released in the form of photons when electrons on the conduction band transit back to the valence band so as to excite corresponding emissions of red light, green light, and blue light. Also, the light emission of quantum dots has a good color purity and a high color gamut.
However, since the size of luminescent particles, such as quantum dots, etc., is very minute and the three dimensions thereof are typically 100 nanometers (nm) or less, the agglomeration phenomenon of luminescent particles in the main material (such as resin, etc.) of the color filter will easily occur, resulting in the problem of uneven light emission of the quantum dot color filter film. Furthermore, since the photoluminescent property of luminescent particles depends on its minute size, after agglomeration of luminescent particles in the main material of the color filter occurs, the photoluminescent performance thereof will be greatly reduced, and electrons on the valence band of the luminescent particles under the light irradiation of back light transit to the conduction band. However, electrons on the conduction band do not transit back to the valence band, but fall in a trap level, and energy is quenched in a non-radiative form, leading to reduced light emission efficiency.